- Tazna Mine (Tasna Mine; Tazna-Rosario Mine), Cerro Tazna, Atocha-Quechisla District, Nor Chichas Province, Potosi Department, Bolivia
- Cabinet, 10.0 x 5.8 x 3.8 cm
This piece came from the great find of Ferberite twins of 2003. It is a rather large and impressive twinned crystal. This piece features the classic, "butterfly" twinning of Ferberite along the a (100) face. It is a good quality, sharp, lustrous, aesthetic jet-black twinned crystal. It has an attractive "open" or "butterfly" form. Twinned crystals from Bolivia are becoming increasingly difficult to obtain in recent years as the price of Tungsten ore has driven the miners to throw nearly all the Ferberite into the crusher, causing thousands of specimens to be lost forever. These twins are definitely the most highly sought after crystal habit from this locality.